OpenStack Compute (nova)

Make hairpin behavior for a VIF configurable

Registered by Sean M. Collins

Nova's libvirt driver currently enables hairpinning, which breaks IPv6. Nova's firewall drivers create rules to prevent IPv6 traffic from hairpinning, but when using Neutron for firewalling/security groups the packets return to the instance and break IPv6. Neutron should pass in an attribute for the VIF when hairpinning needs to be enabled for an interface. This means that when Neutron is being used, Libvirt should not enable hairpinning by default.

This blueprint is the result of a discussion that disables hairpinning in Nova's libvirt driver.

https://review.openstack.org/#/c/56381/

A blueprint has been registered on the Neutron side to return a VIF attribute that Nova will use.

https://blueprints.launchpad.net/neutron/+spec/vif-attribute-for-hairpinning

Blueprint information

Status:
Complete
Approver:
Russell Bryant
Priority:
Undefined
Drafter:
Sean M. Collins
Direction:
Approved
Assignee:
Sean M. Collins
Definition:
Obsolete
Series goal:
None
Implementation:
Blocked
Milestone target:
None
Started by
Russell Bryant
Completed by
Sean M. Collins

Related branches

Sprints

Whiteboard

Implementation blocked on completion of Neutron work.

Ian Wells did a spike on this, and posted his comments in review (https://review.openstack.org/#/c/56381/8/nova/virt/libvirt/driver.py,unified) - it appears that only the libvirt driver has this setting, so it would not be utilized widely. That was at least our conclusion at the time.

(?)

Work Items

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